Internal gauge



March 17, 1.953 R, J, WYNNE 2,631,378

INTERNAL GAUGE A Filed Aug. 12, 1947 30 Fig. 2

Fig. 4

nnentor Gttorneg Patented Mar. 17,1953

UNITED STATES PATENT QFFICEA 3 Claims.

This invention relates to machinists? -precision tools, and more particularlyv to internal gauges, and has for its principal object the provision of a device-of the class described, especially adapted to thev accurate measurement of internal diameters of either parallel or tapered bores.

A further object of the invention is the provision of a gauge that can be pre-set to a desired standard, so that any departure therefrom can be accurately and quickly determined.

vA still further object of the invention is the provision of an internal gauge, having an aldjustable stop, whereby the user is enabled to check the bore ofA a hole at selected points along its axis, and Ithus determine the amount of taper that may exist per unit of length.

These and other objects will become apparent during the course of the following description, taken in connection with the accompanyving drawing, forming a part hereof, and in which:

Figure 1 is a longitudinal cross section through the center line of an embodiment of the invention.

Figure 2 is an elevation, partly in section, of`

the device shown on Figure 1, the adjusting head being removed and being replaced by an indicator dial.

Figure 3 is an end elevation showing the adjusting head.

Figure 4 is an velevation of a spring washer.

used in the device.

Figure 5 is a section taken on line'- 5 5 of Figure 1.

Referring to the drawing in detail, a parallel tube 'I is shown having an internal thread extending inwardly, a relatively short distance, at either end. Adjacent one end thereof, three parallel slots 8 are cut through the wall of the tube 1, and are equally spaced around the circumference. The slots 8 are of such a length as to permit the installation of nine steel balls 9 into the inside of the tube 1, and are of such a Width as to prevent their lateral displacement therefrom, while still allowing a limited movement in that direction.

As can be seen on Figures 1 and 5, the balls 9 are arranged in the following order, a single ball coincident with the center line -of the device, a cluster of three balls contiguous with the rst one, each being aligned witha slot 8, and being coplanar with one another, a second single ball symmetrical to the first one relative to la plane coincident with the centers of the three balls, a second cluster of three balls arranged in identical relationship to the second single ball -as the first cluster is to the rst single ball, and a third single ball symmetrcalwith the first single ball relative to the entire group.

2 The balls 9 are held in' place in the end of' the. tube 'I` by a threaded4 plug I0 screwed in the end thereof. The plug I0 is prefcrablyiformed with a centrally located depression on the inner end thereof, complementary to the contour v`of the contiguous ball 9. The ballsy 9 are yieldingly restrainedv from longitudinal motion in thei other direction by the combination of a rod guide II, a rod I2, a compression spring I?.- and an adapter tting I4. 'I'he guide II, which isadapted to slide freely but not looselyV inthe interior of the tube l, is formed with a yball engaging depression similar to that of plug I0, andonits opposite end isV provided witha centrally located tapped hole which engages the threaded end of the rod I2. If desired, the guide II and the rod I2 can be formed. integral with one another.

The adapter fitting I4 ist formed of two concentric threaded portions, separated by a ange or collar, and having a centrally located bore adapted to permit sliding motion ofv therod I2 therein. As can be clearly seenon Figure l., lafter the balls 9 and the plug I9 have been installed, the guide II and attached rod I2 are inserted with the spring I3 surrounding the rod I2. The tting I4 is then mounted on the rod I2 and screwed into the tube l, thus holding the assembly together. A stopcollar I5is:

mounted on the protruding endof the.y rod I2,.

in order to relieve the balls'v 9 of the pressure exerted-by the spring I3.

It will be apparent that any. movement ofthe'- balls 9A in the slots 8, toward the center` of the.`-

tube 1, will cause anA` increase in the' center' dis-- tance of the extreme' ball-s, and consequent movement of the rod I2. Thereforaas'thegauge! is passed through a machined hole', any varia-- tion in the longitudinal position of the rod l2 will be indicative of a variation in the diameter' ofthe hole. Outward movement of the rod I2y is caused by the cam action of the balls being' pressed inwardly, and motion of the rod I2 in the opposite direction is caused by 4the pressure of the spring which acts to spread the balls outwardly upon any increase in diameter of' thel hole being measured.

For use in the measurement of' tapered holes, o'r the checking of diameters at selected depths',

a collar I6 is adjustably mounted on the outside; of the tube l, and is adapted to register with` graduations I1 marked on the' tube.

In the embodiment of the invention shown on Figure l, an adapter sleeve I8 engages the protruding threaded end of the fitting Ill, and housesl stop collar I5 and the protruding end of rodV I2; The remote end ofA the/sleeve I3 is threaded externally to engage a ange I9, and is threaded internally to receive an adjusting screw 201 The flange I9 is fixedly mounted on the sleeve I8, and

is locked in place thereon by a set screw 2|. If desired the flange can be made an integral part of the sleeve I8.

The adjusting screw 20, which has a single 1. An internal gauge comprising a cylindrical body, said body having a plurality of longitudinal slots at one end thereof, a plurality of balls contained in said body, said balls being arranged lead of 40 pitch, is reduced at its inner end, and 5 in a plurality of rows of three balls in each row is ground square to accurately match the engaging end of the rod l2. A dial nut 22 is locked in place on the screw 2D by means of a set screw 23, and is adapted to form a shoulder against which a dial 24 is rotatably mounted on the screw 20. The dial 24 comprises a dished disc having its periphery of the same diameter as, and adjacent to, the periphery of the flange I9, and being graduated on the outside to form twenty-five equal divisions. A washer 25 contacts the outer side of the dial 24, and it in turn is contacted by a spring washer 26. The spring washer 26 is formed with laterally displaced tongue portions 21, as shown on Figure 4, which are adapted to exert a pressure against any contacting surface. A lock nut 28, mounted on screw 20, contacts the spring washer 26 on one side, and on the outer side bears against an adjusting screw hand nut 29.

Dial nut 22 is locked in place on the screw 20, and then dial 24, washers 25 and 25 are mounted in the order named. The lock nut 28 is then screwed down until the required amount of compression is exerted by washer 26 to prevent dial 24 from turning too freely on the screw 2G, and the hand nut 29 then contacts, and is locked in place by, the lock nut 28.

A pointer 30 is attached to the ange I9 and is adapted to register with the graduations of the dial 24. It will be obvious that rotation of the screw 28 an amount necessary to move the dial through an angle corresponding to one space, will cause it to advance or retract one one-thousandth part of an inch, as the product of one twenty-fth and one fortieth is one thousandth.

In use, a standard ring gauge of suiiicient length is placed over the two clusters of balls 9, and screw 20 is advanced until the balls contact the gauge. The dial is then revolved upon the screw until the zero mark registers with the pointer. The zero setting now represents a standard. By retracting the adjusting screw, inserting the gauge into a bore to be checked, and then advancing the screw the amount necessary to cause the balls to again make contact, any deviation from the standard setting of the device will be apparent from the relative positions of dial and pointer.

In the embodiment shown on Figure 2, an adapter sleeve 3| is provided to carry a dial indicator 32, mounted as shown to indicate movement of the rod l2 with which it is in contact.

If desired, the adapter sleeves i8 and 3l may be provided with holes or openings for the purpose of observing the contact of the adjusting screw or the dial indicator, respectively, with the rod I2.

While I have disclosed a preferred embodiment of my device, various modications may be made, such as the elimination of a single ball and its contiguous cluster, or the device could even be designed to function with one cluster of balls contacting the stop IB and a single centrally located ball contacting the guide i i; I therefore, do not wish to be limited by the speciiic embodiment illustrated, but only to the extent embraced by the spirit and scope of the appended claims.

I claim:

and having a single ball between said rows contacting the balls of each of the adjoining rows, the balls of the rows partially projecting through said slots and adapted to contact the wall of a bore to be measured and to be pushed inwardly by said wall, a sliding member resting on at least one of said balls and adapted to be moved by cumulative displacement of said balls, means on said sliding member for creating resilient pressure on said balls, means for limiting the movement of said sliding member toward said balls; and an indicating means associated with said sliding means for reading the size of the bore.

2. An internal gauge comprising a hollow cylindrical body having a plurality of longitudinal slots at one end thereof; a plurality of balls in said body with each of the balls loosely contacting at least one other ball, some of the balls partially projecting through each of said slots, a sliding member inside of said body one end of which rests on at least one of said balls, means for yieldingly forcing said sliding member against at least one of said balls; means for limiting the movement of the sliding member toward said balls and an indicating means associated with said sliding means for reading the size of the bore which is measured.

3. An internal gauge comprising a hollow cylindrical body having a plurality of longitudinal slots at one end thereof; a plurality of balls arranged in layers so that at least one ball inl each of said layers partially projects through one of the slots, said layers being separated by single balls, said balls projecting through said slots being adapted to contact the wall of a bore to be measured and to be pushed inwardly thereby; a sliding member in said body, one end of which rests on at least one of the balls, means for yieldingly forcing said sliding member against said ball, means for limiting the motion of the sliding member toward said balls; an indicator attached to the body, an adjustable dial adapted to be set at any standard position, and means associated with said sliding member for measuring the deviations from said standard position.

ROBERT JOHN WYNNE.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 484,813 Nugent Oct. 25, 1892 1,048,073 Hirth Dec. 24, 1912 1,420,951 Bartholdy June 27, 1922 1,423,542 Rockwell July 25, 1922 1,644,535 Bartholdy Apr. 3, 1928 `2,047,607 Zimmerman July 14, 1936 2,232,340 Olson Feb. 18, 1941 2,312,222 Tanner Feb. 23, 1943 2,348,643 Poole May 9, 1944 p FOREIGN PATENTS Number Country Date 218,397 Switzerland Apr. 16, 1942 227,618 Switzerland Sept. 1, 1943 230,931 Switzerland May 1, 1944 376,052

Germany May 23, A1923Y 

